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Only the Optimized CM13 and the AOSP 6.0 roms have a custom kernel, namely Alucard kernel.
Synergy also provides a kernel with his CM13 builds, but it is more of a modified stock cm kernel.
You could try flashing the boot.img from the Optimized CM13 zip on any other CM13 based rom. It should give you Alucard's kernel on that rom, but you might encounter bugs.
Is there a custom kernel for 5.1.1 Miui based ROM?
why there is no custom kernel for I9505 CM MM,N roms?
can anyone please build a custom kernel for cm roms?
Because there are no kernel developers for the S4.
Can anyone please build a custom kernel for Cm13 MM roms
Any kernels for the stock rom based on pie?